A caliper is a device that pinches brake discs with any given force to create braking force. RTRI has developed a pneumatic floating caliper that is endowed with simplicity and outstanding maintainability without requiring the use of a pneumatic-hydraulic conversion device (i.e. a booster cylinder) and is interchangeable with existing lightweight and compact hydraulic calipers used on Shinkansen vehicles. It is further possible to configure it to the same size as a hydraulic caliper. Testing on a braking test bench has verified that the pneumatic floating caliper offers a level of brake performance equivalent to that of the hydraulic caliper, and that the increase in temperature of the diaphragm has been suppressed to a level that does not adversely affect its lifespan thanks to the adiabatic piston arranged between the diaphragm and the brake lining.