A glass panel unit includes: a first glass pane; a second glass pane facing the first glass pane; a frame member; an evacuated space; and a gas adsorbent. The frame member hermetically bonds the first glass pane and the second glass pane. The evacuated space is surrounded with the first glass pane, the second glass pane, and the frame member. The gas adsorbent is placed in the evacuated space. The gas adsorbent contains a getter material. The getter material contains a plurality of particles of a zeolite crystal. At least one particle accounting for a half or more of a total weight of the plurality of particles has a particle size equal to or greater than 200 nm. An activable temperature of the at least one particle is equal to or lower than 400° C.

Methods for selecting titania-doped quartz glass which experiences a reduction in OH group concentration of less than or equal to 100 ppm upon heat treatment at 900° C. for 100 hours as suitable material for the EUV lithography member.

A joint structure jointing a ceramic member and a metal member is a joint structure jointing a ceramic member and a metal member that are provided in a device provided on a portion through which gas passes. The joint structure has a joint portion that joints the ceramic member and the metal member. The joint portion includes a glass portion made of a glass and a metal solder portion having higher corrosion resistance with respect to the gas than the glass. An area where the metal solder portion contacts to the gas is larger than an area where the glass portion contacts to the gas.

A method of masking glass in an ion exchange bath includes applying a dissolvable sealant to a cover material, adhering the cover material to a glass part to form a mask on the glass part, immersing the glass part into an ion exchange bath. removing the glass part from the ion exchange bath, and using a solvent to dissolve the sealant and the cover material from the glass part. A mask on glass having a piece of glass, and a dissolvable sealant on a cover material, the dissolvable sealant comprising an inorganic material and a silicate, the dissolvable sealant between the cover material and the piece of glass.

A method of masking glass in an ion exchange bath includes applying a dissolvable sealant to a cover material, adhering the cover material to a glass part to form a mask on the glass part, immersing the glass part into an ion exchange bath. removing the glass part from the ion exchange bath, and using a solvent to dissolve the sealant and the cover material from the glass part. A mask on glass having a piece of glass, and a dissolvable sealant on a cover material, the dissolvable sealant comprising an inorganic material and a silicate, the dissolvable sealant between the cover material and the piece of glass.

A method of integrally bonding a glass element to a support element, the method comprising a step of inserting at least one contact element into a contact recess in a surface of the support element. In addition, the method comprises a step of placing the glass element on a portion of the contact element which portion protrudes beyond the surface, and a step of locally heating the contact element in order to connect the glass element to the support element via the contact element. The method also comprises a step of coating at least a part of the contact recess with a separating layer prior to the step of insertion.

A glass panel unit includes: a first glass pane; a second glass pane facing the first glass pane; a frame member; an evacuated space; and a gas adsorbent. The frame member hermetically bonds the first glass pane and the second glass pane. The evacuated space is surrounded with the first glass pane, the second glass pane, and the frame member. The gas adsorbent is placed in the evacuated space. The gas adsorbent contains a getter material. The getter material contains a plurality of particles of a zeolite crystal. At least one particle accounting for a half or more of a total weight of the plurality of particles has a particle size equal to or greater than 200 nm. An activable temperature of the at least one particle is equal to or lower than 400 C.

A glass panel unit includes: a first glass pane; a second glass pane facing the first glass pane; a frame member; an evacuated space; and a gas adsorbent. The frame member hermetically bonds the first glass pane and the second glass pane. The evacuated space is surrounded with the first glass pane, the second glass pane, and the frame member. The gas adsorbent is placed in the evacuated space. The gas adsorbent contains a getter material. The getter material contains a plurality of particles of a zeolite crystal. At least one particle accounting for a half or more of a total weight of the plurality of particles has a particle size equal to or greater than 200 nm. An activable temperature of the at least one particle is equal to or lower than 400oC.