Manganese selenide (MnSe) crystalline thin film was produced with chemical bath deposition on substrates commercial glass). Transmittance, absorption, optical band gap and refractive index were investigated by UV/VIS spectrum.The hexagonal form was observed in the structural properties in XRD. The structural and optical properties of the MnSe thin films were analyzed at different pHs. SEM and EDX analysis were used for the surface analysis in the films. The films had the best crystalline at pH: 9.At pHs of 11 and 10 the MnSeO4 structure was observed. The films with the lowest film thickness were found in baths prepared with pH: 11. The highest refractive index was observed in films produced with a pH of 10 at a film density of 1.96. The gram size of MnSe thin films has a higher value at pH: 9.