To solve the conventional inconvenience that independent ten keys with excellent operability can not be equipped in preference of portability and compactness of the information processor such as a notebook type personal computer or a handy terminal for business.

This processor is composed of a device main body 1 provided with a wireless reception part 8 and a demodulation part 71 for converting data received by the wireless reception part to key codes and a ten-key unit provided with a battery 36 for a power source, a key data detection part 66 for detecting key-inputted key data, a key code generation part 61 for transmitting the key data detected by the key data detection means to the device main body, a modulation part 62 for modulating the key codes generated by the key code generation part and a wireless transmission part 40 for transmitting signals from the modulation part to the device main body. The ten-key unit is housed inside the housing part 7 of the device main body so as to be freely taken in and out.