An oscillator that can suppress a solder crack caused by a temperature change by a simple structure at low cost and improve heat cycle resistance performance is provided. The oscillator includes an epoxy resin board and an electronic component mounted on the board. Two-terminal electrode patterns are formed on the board, and connected to terminal electrodes of the electronic component by solder. A projection is formed on each of the electrode patterns at a part connected to a corresponding terminal electrode to create a space between the terminal electrode and the electrode pattern, and the solder forms a fillet in the space. This contributes to enhanced adhesion strength of the solder.