The OMDR (optical-microwave double resonance) spectrum of /sup 87/Rb with the aim of using a frequency-stabilized GaAs semiconductor laser instead of an Rb lamp as a pumping source in a gas-cell-type Rb frequency standard. Natural isotope /sup 87/Rb was sealed in a glass cell with buffer gases (Ar/N/sub 2/=1.2, total pressure=39 torr). The double resonance signal in the 5P/sub 1/2/(F=2) from 5S/sub 1/2/(F=1) transition appearing at the resonance to the F=2 from 1 hyperfine transition of the 5S/sub 1/2/ state was detected. The optimum operational cell temperature was 56 degrees C. The peak-to-peak frequency width of the atomic hyperfine resonance discriminator used to stabilize the microwave frequency shifts induced by detuning of the laser frequency, changes in the laser and microwave powers, and temperature drift of the cell were investigated. >