according to one embodiment of the invention , the projection device features a power - supply control section which selectively supplies power from a power - supply portion . the projection device further comprises a lamp section which emits projection light and radiates the projection light ; an operation portion having a plurality of operation switches ; a control portion which compares input data , perhaps obtained by depression of predetermined operations switch with a pre - stored authentication code and controls the power - supply control portion to supply the power to the lamp section based on the result of the comparison .