There is provided a mode-locked laser device (10) including: a resonator (34) a solid-state laser medium (26) that is disposed in the resonator (34) and outputs oscillation light in accordance with the incidence of excitation light a saturable absorber (28) that is disposed in the resonator (34) and induces soliton mode-locking a group velocity dispersion correction component (30) that is disposed in the resonator (34) and controls group velocity dispersion in the resonator (34) and an excitation portion (32) that causes excitation light to be incident at the solid-state laser medium (26), wherein a resonator length of the resonator is at least a resonator length with which soliton mode-locking is inducible and is less than a resonator length with which non-soliton mode-locking is inducible.
