A semiconductor device according to embodiments includes a normally-off transistor having a first electrode, a second electrode, and a first control electrode, a normally-on transistor having a third electrode electrically connected to the second electrode, a fourth electrode, and a second control electrode, a first element having a first end portion electrically connected to the first control electrode and a second end portion electrically connected to the first electrode, and the first element including a first capacitance component; and, a second element having a third end portion electrically connected to the first control electrode and the first end portion and a fourth end portion, and the second element including a second capacitance component, wherein, when a threshold voltage of the normally-off transistor is denoted by Vth, a maximum rated gate voltage of the normally-off transistor is denoted by Vg_max, a voltage of the fourth end portion is denoted by Vg_on, the first capacitance component is denoted by Ca, and the second capacitance component is denoted by Cb, Vth