In general, according to one embodiment, a DA converter configured to convert a digital signal comprising n (n>1) bits to an analog current to output the analog current from an output terminal, includes n voltage-current converters. Each of them corresponds to each bit of the digital signal and is configured to generate a current depending on the corresponding bit. A k-th (k is an integer of 0 to n−1) voltage-current converter includes a first transistor whose threshold voltage is adjustable. The first transistor includes a semiconductor substrate, a first diffusion region, a second diffusion region, an insulating film, a charge accumulating film, and a gate.