An oscillator includes: a resonator element; a circuit element; and a container including a substrate mounted with the circuit element, in which the circuit element includes a first coupling terminal coupled to the resonator element, a second coupling terminal coupled to the resonator element and aligned in a first direction with the first coupling terminal in the first direction, and an output terminal disposed adjacent to the first coupling terminal in a second direction orthogonal to the first direction, in the second direction orthogonal to the first direction, and in which the substrate includes a first surface mounted with the circuit element and a second surface, and the substrate includes a first coupling electrode provided on the first surface and coupled to the first coupling terminal, a second coupling electrode coupled to the second coupling terminal, an output electrode coupled to the output terminal, a first coupling wiring provided on the second surface and coupled to the first coupling electrode, a second coupling wiring coupled to the second coupling electrode, an output wiring coupled to the output electrode, and a shield wiring that is provided between the first coupling wiring and the output wiring and to which a direct-current potential is applied.