An ultrasonic device unit includes an ultrasonic device having a device-side terminal, a reinforcing plate having a support adapted to support the ultrasonic device, and a flexible printed wiring board to be connected to the ultrasonic device, the flexible printed wiring board is provided with a connection to be connected to the device-side terminal, and a bend continuous with the connection, extending away from the ultrasonic device, and having an end edge parallel to an extending direction, and the reinforcing plate is provided with a bending guide provided to a first side parallel to a first direction crossing the extending direction, having a circular arc curved surface convex away from the support, and opposed to the bend, and a guide surface disposed at an end in the first direction of the bending guide, and adapted to guide the end edge of the bend.