A stator includes a stator core, which has a plurality of stacked electromagnetic steel sheets, caulking portions configured to fix the plurality of electromagnetic steel sheets to each other, and a plurality of slot portions open toward an inner circumference side and arrayed along a circumferential direction. A number Q (an integer of 1 or greater) of the caulking portions, a number S of the slot portions and a number P of the poles satisfy Q≦S and Q=P×n/2 (where n is an integer of 1 or greater). The stator is preferably part of a motor for a compressor.