PROBLEM TO BE SOLVED: To provide a driving state determination device capable of determining a state in which the mind and the body are both activated by visualizing a sense of expectation and a sense of achievement.SOLUTION: A driving state determination device includes somatic nervous system activity degree detection means for detecting a physical somatic nervous system activity degree t of a driver, autonomic nervous system activity degree detection means for detecting a mental autonomic nervous system activity degree g of the driver, and drivers state estimation means for estimating states of the drivers mind and body based on the detected somatic nervous system activity degree t and the autonomic nervous system activity degree g. The drivers state estimation means includes a coordinate system defined by the somatic nervous system activity degree t and the autonomic nervous system activity degree g, in which a balance zone A is formed, including part of a balance line L in which the ratio of the somatic nervous system activity degree t to the autonomic nervous system activity degree g is constant, and determines that the drivers mind and body are in the activated states in which the somatic nervous system and the autonomic nervous system are balanced when the states of the drivers mind and body based on the somatic nervous system activity degree t and the autonomic nervous system activity degree g are within the balance zone A.SELECTED DRAWING: Figure 2
