According to one embodiment, an X-ray tube includes a cathode including a filament, an anode target, and an envelope. The cathode includes a metal lead wire supporter which is exposed outside the envelope, which is configured as a part of the envelope, and to which a lead wire as a power supplier to the filament is attached such that the lead wire passes both inside and outside of the envelope, and a metal filament supporter fixed on the lead wire supporter, being in contact with the lead wire supporter, and supporting the filament.