A method of manufacturing a semiconductor laser element includes: providing a nitride semiconductor structure with a target emission wavelength λo, the nitride semiconductor structure having a light emission-side surface and a light reflection-side surface; forming an emission-side mirror on the light emission-side surface; and forming a reflection-side mirror on the light reflection-side surface. The semiconductor laser element has an actual wavelength λa, which is 500 nm or more and is in a range of λo±X nm (5≤X≤15). A reflectance of the emission-side mirror is lower than a reflectance of the reflection-side mirror and increases in accordance with an increase in wavelength in a range of λo±X nm.