Provided is an optical unit comprising a shake detecting sensor which is less likely to unnecessarily vibrate even with the optical unit being designed to have a thinner profile. At a first step in the assembly of an optical unit provided with a shake correction mechanism, a module cover is mounted on a fixed body with a spring member therebetween and a movable module driving mechanism is provided between the module cover and the fixed body. At a second step, an image-capturing unit is inserted into the interior of the module cover by way of a fixed-body-side opening portion and a module-cover-side opening portion, and at a third step, a holding member is attached to a module cover.