The invention provides an irradiating device and a program which can appropriately set a cross sectional shape of human tissue at a time of incising the human tissue by beam irradiation. For example, when a cornea (100) is incised by an irradiating device which outputs femtosecond laser, a cross sectional shape in an intersecting direction to a direction of advancing to a back surface side from a front surface side of the cornea in an incision (101) is set to a non-rectilinear shape, for example, a circular arc shape. As a result, there can be achieved effects such as suppression of drawing of the incision in the case of inserting the instrument by opening the incision, and self-closing of the incised site.
