To provide a remote control transmitting device having operability enhanced by easily switching a mode of an operating key by one hand.

In a current changing circuit 2 to produce a current change in two electrodes provided on the outer surface of a remote control transmitter 1 such as the back surface for instance, and an electric current and voltage converting circuit 3 to produce a mode switching voltage in response to the current change, a current change is produced by short-circuiting if a user touches the both electrodes mentioned above, and a mode can be selected by producing a mode switching voltage in response to the current change. A key code signal can be generated in a different form for every mode by a key code signal generating circuit 4 to produce two kinds of key code signals which are different for every mode and set by the mode switching voltage, in response to an operating key signal of an operating key detecting circuit 51, therefore, the number of the operating keys can be practically doubled. Since the mode of the operating key can be switched by lightly touching the back surface of the remote control transmitter 1 by a hand for example, operability can be enhanced.