First-principles calculations have been utilized to investigate the electronic and optical properties of GaTe monolayer. The GaTe single-layer reveals a proper bandgap and suitable optical properties that not observed in the other layered materials, including absorption coefficient larger than 10(4) cm(-1) at the visible light range. Combining the electronic and optical properties, GaTe monolayer has a great possibility to be used as ultraviolet detectors and photovoltaic absorbers. Accordingly, our results suggest significant guidelines for the design of optoelectronic devices that made of layered GaTe. The present work provides useful guidance for further expanding the practical application range of GaTe materials.