A release sheet 1 may include a base material 12 and a release agent layer 11 provided on the base material 12. The release agent layer 11 is composed of a cured product of a release agent composition containing 50 mass % or more of a diene-based polymer. Mooney viscosity (ML.sub.1+4 (100° C.)) of the diene-based polymer measured at 100° C. according to HS K6300 is in the range of 25 to 70, and a ratio (T.sub.Cp/ML.sub.1+4 (100° C.)) of the Mooney viscosity (ML.sub.1+4 (100° C.)) and a viscosity (T.sub.Cp) of a toluene solution of the diene-based polymer is 2.2 or less. This makes it possible to provide a release sheet which can sufficiently suppress adverse effects on electric components and the like, which has a small dependence of release force on peel rate and which can suppress the occurrence of zipping phenomenon, and a pressure-sensitive adhesive article having such a release sheet.

The release agent composition of the invention contains a rubber elastomer (A) and an acrylic polymer (B) containing a structural unit derived from a long-chain alkyl (meth)acrylate (b1) represented by the following formula (1):

##STR00001##

wherein R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents a branched alkyl group having 10 to 30 carbon atoms.

The release agent composition of the invention contains a rubber elastomer (A) and an acrylic polymer (B) containing a structural unit derived from a long-chain alkyl (meth)acrylate (b1) represented by the following formula (1):

##STR00001##

wherein R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents a branched alkyl group having 10 to 30 carbon atoms.