To provide a sealing method of a sensor for improving sealing properties of an inside space where a sensor module is arranged, and to provide a sealing structure of the sensor.

A fluid pressure sensor 1 comprises a body 11 for arranging a strain gauge 20A of the sensor module 20 in the inside and a circuit part 30, and a sealing part 50 formed to inject synthetic resin in a gap with a housing fitted to a fitting wall part 15 of the body 11. Thereby, even in a state where a gasket part 41 of the housing 40 is fitted to the fitting wall part 15, when the gap occurs between the fitting wall part 15 and the gasket part 41, the gap is surely sealed with the sealing part 50 formed of the synthetic resin ejected. Thus, the sealing property of the inside space of the fluid pressure sensor 1 is improved.