VALVE DEVICE

A valve device is provided that is a gas-driven type, is capable of mounting various electronic devices, and solves problems involving wiring or battery replacement. The problem is solved by a valve device including a piston member that drives a diaphragm, an actuator part that receives supply of high-pressure air and drives the piston member, a coil spring that presses the piston member in a direction reverse to a driving direction of the actuator part, and a power generation unit provided in a power generation unit-housing part serving as a supply path of high-pressure air to the actuator part and including a screw rotated by air flow and a commutator generator coupled with the screw. The power generation unit generates power using the high-pressure air supplied to the actuator part and a portion of energy stored in the coil spring.