In order to provide a wavelength tunable surface emitting laser capable of improving a wavelength tuning efficiency, provided is a surface emitting laser, including: a first reflector (100)； a semiconductor cavity (150) including an active layer (120)； and a second reflector (110), the first reflector, the semiconductor cavity, and the second reflector being formed in the stated order, a gap portion (130) being formed between the first reflector and a semiconductor layer, a cavity length being tunable, in which the surface emitting laser has a high reflectivity structure formed between the gap portion and the semiconductor cavity, and an expression of "(λ/2)×m+λ/8<；L<；(λ/2)×m+3λ/8" is satisfied, where L is an optical thickness of the semiconductor cavity, m is an integer of 1 or larger, and λ is a center wavelength of laser oscillation.
