PURPOSE: To obtain a production method of a surface pressurization type semiconductor pressure sensor capable of holding the application thickness of silicone gel minimum in an application process of silicone gel and uniformly applying silicone gel to the whole surface of a pressure sensitive diaphragm chip and a wire.

CONSTITUTION: A pressure sensitive diaphragm chip 1 is mounted on a printed board 3, the surface electrode of the pressure sensitive diaphragm 1 and the printed board 3 are connected with a wire 5 and under the condition that the diaphragm chip 1 and the wire 5 are surrounded and a case 6 is assembled on the printed board 3, silicone gel is injected up to a level where the pressure sensitive diaphragm 1 and the wire 5 are buried in a silicone gel layer within the case 6. Thereafter the residual silicone gel 8 is drawn out from the case 6 with the vacuum method, the whole surface of the pressure sensitive diaphragm chip 1 and the wire 5 are coated and silicone gel 8 is uniformly applied in thickness not much exceeding 30-80μm.