Provided is a capacitive humidity sensor whereby it is possible to prevent infiltration and discharge of excess moisture without forming a moisture-impermeable protective film. A first slit 4 is formed between a surrounding electrode 51 and most of a peripheral edge section of a lower electrode 31. A moisture-sensitive film pattern 7 fills the first slit 4 formed between the surrounding electrode 51 and most of the peripheral edge section of the lower electrode 31, and is provided with a second slit 8 for causing the surrounding electrode 51 to be continuously exposed, the second slit 8 being provided along the surrounding electrode 51. An upper electrode pattern 9 is formed so as to cover most of a peripheral edge section of a moisture-sensitive film 71. The upper electrode pattern 9 is formed so as to fill the second slit 8 in the moisture-sensitive film pattern 7.