To provide a pressure adjuster for easily realizing adjustment for stable burning even at the time of connecting burning equipments whose set entrance pressures are different from each other.

In this pressure adjuster, a diaphragm 5 is arranged inside an adjuster main body 4 having a gas inflow port 2 and a gas outflow port 3, and a spring pressure is allowed to act on the diaphragm 5, and a valve body 10 moving back and forth based on the movement of the diaphragm 5 is mounted on the gas inflow port 2 side so that inflow gas quantity can be adjusted. In this case, one edge part of a pressurizing spring 8 whose other edge is butted to the diaphragm 5 is received by a spring bearing 13. The receiving position in the adjuster in body 4 of the spring bearing 13 can be gradually adjusted and changed according to an operation from the outside part of the adjuster main body 4.