An atomic oscillator includes a gas cell encapsulating metal atoms, a coil disposed in a periphery of the gas cell, a laser source adapted to emit excitation light toward the gas cell, a heater adapted to heat the gas cell, and a wiring board adapted to supply the heater with power, and a plus line forming a plus current channel for the heater and provided to the wiring board, and a minus line forming a minus current channel for the heater and provided to the wiring board are disposed close to each other.