In a driving assisting device in which a receiver acquires the time-series traffic signal information regarding a lighting state of the traffic signal and a display and a speaker provide the lighting time information regarding a time remaining until a red signal of the traffic signal changes, the display and the speaker provide the lighting time information regarding the time remaining until the red signal of the traffic signal changes only when it is confirmed from the traffic signal information that a signal after change of the red signal permits traveling of the host vehicle. Accordingly, for example, for a light color change or the like in which an arrow lamp other than the traveling direction lights up after a red signal, a red signal waiting time is not displayed. This makes it possible to suppress factors inducing a careless driver to start driving.