To provide a method for producing an acrylic polymer emulsion by which an acrylic polymer having two peaks in a GPC measurement is produced by a simple method; to provide the acrylic emulsion obtained by the method; to provide an adhesive obtained by heating and drying the acrylic polymer emulsion, and having high adhesive force and high holding power; and to provide an adhesive sheets having the adhesive as an adhesive layer.

An emulsion to be dropped, containing a reactive monomer consisting essentially of a (meth)acrylic ester is dropped in an aqueous medium while regulating a reaction temperature of the first step from the start so as to be 40-65°C, and changing the reaction temperature from the reaction temperature at the first step to a reaction temperature of 70-95°C at the second step within a range regulated so that the proportion dropped from the start of the dropping is 10-90% of the whole dropping amount to polymerize the reactive monomer.