This invention is to provide a piston-type compressor that assures optimal lubrication by supplying oil in plentiful quantity to a sliding portion in a cylinder block having cylinders formed therein, through which pistons slide reciprocally. A crankcase is defined by a cylinder block 1 having formed therein a plurality of cylinders 17 through which pistons slide, and a housing mounted at the cylinder block 1, and as a shaft passing through the crankcase rotates, a swashplate disposed inside the crankcase is made to rotate, thereby engaging the pistons to reciprocally slide through the cylinders. At the cylinder block 1, an inbound oil guide passage 35 having one end thereof made to open over an area at the end surface of the cylinder block facing the crankcase between adjacent cylinders 17 and another end thereof connecting to a sliding portion inside the cylinder block.