A watch unit having a time-displaying section, including a reflection-type polarizing film 14 disposed on an upper portion or a lower portion of the time-displaying section or a portion comprising a part of the time-displaying section, an optical modulation section which varies the ratio of a transmission axis to a reflection axis of the reflection-type polarizing film 14, and a shutter function to shield a portion of or all of the watch unit having the time-display section by varying the reflection intensity and the transmission intensity in relation to the light incident direction using the reflection-type polarinzing film 14 and the optical modulation section, to enhance the appearance and to improve the versatility of the watch unit.