A power supply unit of an aerosol generating device, includes: a power supply; a positive electrode-side discharge terminal and a negative electrode-side discharge terminal to which a load configured to generate aerosol from an aerosol source by consuming electric power supplied from the power supply or a coil configured to transmit electric power to the load by electromagnetic induction is connected; and a circuit substrate including a first surface on which the positive electrode-side discharge terminal is mounted and a second surface which is a back surface of the first surface and on which the negative electrode-side discharge terminal is mounted.