Air compressor

In an air compressor including a main frame for mounting a motor, and a cylinder fitted with a piston body, the motor capable of driving the piston body to conduct reciprocating motion to produce in the cylinder compressed air which can enter an air storage container via a plurality of exit holes defined at a top wall of the cylinder;

• wherein the improvements comprises:
• the top wall of the cylinder is provided with the plurality of exit holes having air blocking walls which isolate the exit holes from each other at a certain extent, and the exit holes are regulated by a control mechanism to be opened or closed, the control mechanism including a resilient sheet having a root and a plurality of branches extending from the root and corresponding to the exit holes, whereby when the compressed air produced in the cylinder pushes the branches of the resilient sheet up to open the exit holes, the instantaneous high-pressure air that flows through the exit holes can be restrained by the air blocking walls to prevent the air from interfering with movements of the branches of the resilient sheet, so that the piston body can conduct reciprocating motion more smoothly and thus the performance of the air compressor can be increased.