PURPOSE: To form sealed chambers with high yield by a method wherein a semiconductor wafer in which a plurality of diaphragms are formed and a base wafer are piled with a glass film in between and heated, so that both wafers are welded.

CONSTITUTION: A silicone wafer 1 on one side of which a resistive component is diffused and on another side of which a plurality of diaphragms are formed by etching and a base wafer 3 on which a glass film 4 of boron silicate glass or lead glass is adhered by a powder deposition metod are piled. These piled wafers are heated to the temperature higher than the softening point of glass and the wafers 1, 3 are welded by the glass, so that sealed chambers are formed. Then electrodes 2 are deposited on the diaphragm surface and formed by photo- patterning and etching. Each unit is separated along separating lines 6 into a chip. The perfect welding is obtained by using a jig 7 which is so formed as to have its circumference thicker than its center part to heat the central parts of the wafers 1, 3 faster than the peripheral parts thereof.