A fan device for a dishwasher, the dishwasher comprising an inner container defining a washing chamber, wherein the fan device comprises: a shell defining an air duct communicating the washing chamber with the outside; a fan configured to establish an airflow passing through the air duct to the outside to ventilate the washing chamber; a humidity detection device mounted on the shell, the humidity detection device comprising a humidity detection element fixed on a side wall of the air duct, the humidity detection element comprising a detection end positioned in the air duct, the humidity detection element being configured to detect a humidity in the air duct through the detection end; and a controller electrically connected with the humidity detection element and the fan, and configured to control an operating state of the fan according to the humidity; wherein the shell is provided with a first positioning and fixing structure, the humidity detection device comprises a second positioning and fixing structure, the humidity detection element is fixed to the second positioning and fixing structure, the first positioning and fixing structure is fitted with the second positioning and fixing structure so that the humidity detection element is fixed on the side wall of the air duct; characterized in that the humidity detection element is disposed through the first positioning and fixing structure so that the detection end is positioned in the air duct and wherein the humidity detection device comprises a cover, one end of the cover is fixed to the second positioning and fixing structure so that the cover covers the humidity detection element, the other end of the cover is disposed through the first positioning and fixing structure to be fixed to the side wall of the air duct, the detection end is accommodated in the other end of the cover and the other end of the cover defines a plurality of through holes communicating with an inside of the cover. a shell defining an air duct communicating the washing chamber with the outside; a fan configured to establish an airflow passing through the air duct to the outside to ventilate the washing chamber; a humidity detection device mounted on the shell, the humidity detection device comprising a humidity detection element fixed on a side wall of the air duct, the humidity detection element comprising a detection end positioned in the air duct, the humidity detection element being configured to detect a humidity in the air duct through the detection end; and a controller electrically connected with the humidity detection element and the fan, and configured to control an operating state of the fan according to the humidity; wherein the shell is provided with a first positioning and fixing structure, the humidity detection device comprises a second positioning and fixing structure, the humidity detection element is fixed to the second positioning and fixing structure, the first positioning and fixing structure is fitted with the second positioning and fixing structure so that the humidity detection element is fixed on the side wall of the air duct; characterized in that the humidity detection element is disposed through the first positioning and fixing structure so that the detection end is positioned in the air duct and wherein the humidity detection device comprises a cover, one end of the cover is fixed to the second positioning and fixing structure so that the cover covers the humidity detection element, the other end of the cover is disposed through the first positioning and fixing structure to be fixed to the side wall of the air duct, the detection end is accommodated in the other end of the cover and the other end of the cover defines a plurality of through holes communicating with an inside of the cover.