In an electric screen device (2) which is constituted of a pair of electrode members (12 and 12) opposedly positioned on both sides of a water inlet channel (1) and a DC pulse impressing device (13) for impressing a DC pulse across the members (12 and 12) and checks the entrance of a living thing into the channel (1), the product of the peak value of the electric field created between the members (12 and 12) and the body length of the living thing to be checked is more than 0.1 V, the impressing time of the DC pulse falls within a range from (2) msec to 200 msec, and the duty factor of the DC pulse is less than 0.5.