To provide a pressure detection unit achieving improvement in waterproof property. A pressure detection sensor 10 comprises an element body 18 made of stainless steel, aluminum, or nickel and a sealing resin 68 bonded with the outer surface of the element body 18 in such a manner that the element body 18 surrounds a plurality of lead pins 34. The pressure detection sensor 10 also comprises an annular rough-surfaced section 7 that is formed by laser irradiation and provided on an area of an upper end surface 18a of the element body 18 with which the sealing resin 68 is bonded in such a manner that the rough-surfaced section 7 separates an outer peripheral edge 68a of the sealing resin 68 on the outer surface of the element body 18 from an inner peripheral edge 68b of the sealing resin 68.