A semiconductor laser device includes a base, a semiconductor laser chip and a resin layer enclosing the laser chip. The base may have a monitor photodiode mounted thereon in the vicinity of the laser chip. The resin layer enclosing the laser chip or both of the laser chip and the monitor diode chip is made of a single synthetic resin having a thickness not greater than 500 mu m and also having a surface substantially parallel to an outwardly oriented beam emitting end face of the laser chip. <IMAGE>