A biological signal detection electrode (1, 100, 200, 300) comprising: an electrode element that is made of a conductive material and has a surface; a plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) which are soaked in a drought-resistant electrolytic solution made by mixing conductive physiological saline and glycerin, are placed at predetermined intervals on the surface of the electrode element, are formed to have ends (3A, 103C, 203A, 303A) opposite to the side of the electrode element and to have a diameter of 2 mm or less that allows contact with a scalp of a test subject, without hair being sandwiched between the ends (3A, 103C, 203A, 303A) of the drought-resistant electrolytic solution soaking parts (3,103, 203, 303) and the scalp; and a support part having an upper surface configured for facing the electrode element and a bottom surface opposite to the upper surface, wherein the support part: is formed to have an almost the same height extending between the bottom surface and the upper surface, as the length of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303), has through holes extending between the upper surface and the bottom surface, into which the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are insertable, wherein the bottom surface area is larger than the area of the end surfaces of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303), and is configured to shrink in the height direction by the thickness of the hair sandwiched between the bottom surface and the scalp, when the ends (3A, 103C, 203A, 303A) of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are pushed against the scalp with a predetermined pushing force in the state where the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are inserted into the through holes. an electrode element that is made of a conductive material and has a surface; a plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) which are soaked in a drought-resistant electrolytic solution made by mixing conductive physiological saline and glycerin, are placed at predetermined intervals on the surface of the electrode element, are formed to have ends (3A, 103C, 203A, 303A) opposite to the side of the electrode element and to have a diameter of 2 mm or less that allows contact with a scalp of a test subject, without hair being sandwiched between the ends (3A, 103C, 203A, 303A) of the drought-resistant electrolytic solution soaking parts (3,103, 203, 303) and the scalp; and a support part having an upper surface configured for facing the electrode element and a bottom surface opposite to the upper surface, wherein the support part: is formed to have an almost the same height extending between the bottom surface and the upper surface, as the length of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303), has through holes extending between the upper surface and the bottom surface, into which the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are insertable, wherein the bottom surface area is larger than the area of the end surfaces of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303), and is configured to shrink in the height direction by the thickness of the hair sandwiched between the bottom surface and the scalp, when the ends (3A, 103C, 203A, 303A) of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are pushed against the scalp with a predetermined pushing force in the state where the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are inserted into the through holes. is formed to have an almost the same height extending between the bottom surface and the upper surface, as the length of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303), has through holes extending between the upper surface and the bottom surface, into which the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are insertable, wherein the bottom surface area is larger than the area of the end surfaces of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303), and is configured to shrink in the height direction by the thickness of the hair sandwiched between the bottom surface and the scalp, when the ends (3A, 103C, 203A, 303A) of the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are pushed against the scalp with a predetermined pushing force in the state where the plurality of drought-resistant electrolytic solution soaking parts (3,103, 203, 303) are inserted into the through holes.