A semiconductor laser device includes a semiconductor laser body including
a resonator and having a front end face and a rear end face facing each
other, the resonator being located between the front end face and the
rear end face. The front end face emits principal laser light. A
reflectance control film is disposed on the front end face or the rear
end face of the semiconductor laser body and is made up of either an
aluminum oxide film or a five-layer film including the aluminum oxide
film disposed such that it is the layer in the five-layer film farthest
from the front end face or the rear end face. A silicon oxide film is
disposed on the aluminum oxide film of the reflectance control film and
has a thickness of 20 nm or less.