To provide the input supporting method/device of a stroke command which support the input of the stroke without deteriorating visibility and by which a user with uncertain remembrance can easily input the command.

A command judging part 13 compares the inputted stroke with a stroke command defined in a command definition table 12. An input area control part 16 judges from the compared result the input possible area of the stroke which is inputted next. A stroke input part 15 inhibits the input of the stroke from an input device 20 to an area other than the input possible area on the basis of the judged result.