A peripheral input device capable of carrying a tabular electronic device is disclosed. The peripheral input device includes a base, an inputting module, a supporting mechanism, and a retaining structure. The inputting module, the supporting mechanism, and the retaining structure are disposed on the base. The retaining structure is disposed between the inputting module and the supporting mechanism. The supporting mechanism can provide a plurality of supporting angles for supporting the tabular electronic device stably with the retaining structure. Therefore, the peripheral input device according to the invention can provide functions of supporting and inputting simultaneously, provide a plurality of supporting angles for satisfying view demand of a user to the tabular electronic device during operation, and further can be regarded as a protection cover for the tabular electronic device.