To facilitate setting operation, reduce a burden on an operator in the setting operation, and reduce time for the setting operation when part of a set shedding pattern is set as a reversed pattern.

A loom includes a shedding mechanism capable of electrically controlling individual movements of a plurality of heald frames, and operates the heald frames by driving the shedding mechanism in accordance with a shedding pattern in which the vertical position of each heald frame for each loom cycle is indicated over a plurality of weaving cycles. In the loom, a shedding pattern setting device includes: a display capable of displaying the set shedding pattern on a display screen; and control means enabling the shedding pattern to be set and enabling the set shedding pattern to be changed on the display screen. The control means has a function of specifying any range in the shedding pattern displayed on the display screen and a function of reversing the pattern within the thereby specified range.