An information processing device (10, 110) comprising: a host vehicle information acquisition part configured to acquire host vehicle information on a host vehicle including positional information on a position of the host vehicle; a setting part configured to set an allowable range for a driver 's sight of a host vehicle 's driver by using the host vehicle information including the positional information; a driver monitoring part connected to a driver camera and configured to monitor a direction of the driver 's face and a direction of the driver 's line of sight from an image taken by the driver camera, a driver information acquisition part configured to acquire from the driver monitoring part driver information including information on the direction of the driver 's sight; a determination part configured to determine whether or not the driver is looking at the allowable range based on the allowable range and the driver information including the information on the direction of the driver 's sight; and an output part (40, 50, 60) configured to output a predetermined notification to notify the driver about inattentive driving when the determination part determines that the driver does not look at the allowable range, characterized in that the allowable range includes a first range, a second range, a third range, and a fourth range, wherein the first range is a left front range of the driver, the second range is a right front range of the driver, the third range is a left rear range of the driver, and the fourth range is a right rear range of the driver, and wherein the setting part is configured to set the allowable range to the first range and the second range when the setting part determines that the host vehicle is at an intersection without a traffic light. a host vehicle information acquisition part configured to acquire host vehicle information on a host vehicle including positional information on a position of the host vehicle; a setting part configured to set an allowable range for a driver 's sight of a host vehicle 's driver by using the host vehicle information including the positional information; a driver monitoring part connected to a driver camera and configured to monitor a direction of the driver 's face and a direction of the driver 's line of sight from an image taken by the driver camera, a driver information acquisition part configured to acquire from the driver monitoring part driver information including information on the direction of the driver 's sight; a determination part configured to determine whether or not the driver is looking at the allowable range based on the allowable range and the driver information including the information on the direction of the driver 's sight; and an output part (40, 50, 60) configured to output a predetermined notification to notify the driver about inattentive driving when the determination part determines that the driver does not look at the allowable range, characterized in that the allowable range includes a first range, a second range, a third range, and a fourth range, wherein the first range is a left front range of the driver, the second range is a right front range of the driver, the third range is a left rear range of the driver, and the fourth range is a right rear range of the driver, and wherein the setting part is configured to set the allowable range to the first range and the second range when the setting part determines that the host vehicle is at an intersection without a traffic light.