An ultrasound diagnostic apparatus includes: an ultrasound probe that transmits an ultrasound wave and receives a reflected wave; a display that displays an ultrasound image on a screen; and a hardware processor that activates a screen saver processing of displaying an image hiding information displayed on the screen or a freeze processing of stopping transmission and reception of the ultrasound wave when conditions (A1) or (A2) is continuously satisfied for a predetermined time or more while the ultrasound image is displayed, wherein the conditions (A1) and (A2) are: (A1) a state in which, in an input captured image, a change amount of the probe and surroundings is a first threshold or less; and (A2) a state in which a volume of input voice is a second threshold or less, or a state in which a volume of a specific frequency of input sound is a third threshold or less.