A caliper brake apparatus according to this invention includes: a caliper main body supported on a vehicle body; a brake block that is capable of advancing and retreating relative to the caliper main body and sliding against the disc so as to apply a frictional force to the disc; a pressing mechanism that presses the brake block against the disc using a pressure of a working fluid; and an adjuster that supports the brake block on the caliper main body. The adjuster includes: an anchor pin that is provided to be capable of advancing and retreating relative to the caliper main body and supports the brake block on the caliper main body; a return spring that biases the brake block in a direction heading away from the disc; and a back pressure chamber defined on a back surface of the anchor pin, into which the working fluid is led.