To prevent the occurrence of cracks in a solder for connecting a printed circuit board to an electronic circuit component when the materials of the printed circuit board and the electronic circuit are different.

A surface mounted crystal oscillator 20 comprising a container body and a lid is provided with electrode terminals 13a to 13d provided at four corners on the bottom surface of the container body, and auxiliary terminals 22a to 22c to be welded respectively at an edge section in the longitudinal direction of bottom surface of the container body. As a result, when the crystal oscillator 20 is constituted using electronic component container and mounted on a printed circuit board 30, stress applied to solders 33a to 33d for connecting the electrode terminals 13a to 13d of the container body 2 and lands 31a to 31d of the printed circuit board respectively is dispersed according to the difference between the coefficient of thermal expansion of the container body and that of the printed circuit board 30, and stress applied to the solders 33a to 33d between the electrode terminals 13a to 13d and lands 31a to 31d is reduced.