To perform drying by continuous and efficient microwaves by preventing a decrease in airtightness and influences on a weighting instrument by leakage of the microwaves in a microwave dryer.

The microwave dryer 1A includes: a drying chamber body 5A provided with an opening part 3 for storing dried objects; an open/close door 7A attached to the opening part 3 in an openable/closable state; a microwave irradiator which is attached to the drying chamber body 5A and irradiates the dried objects with microwaves; a seal structure 13 provided with a seal member 11 which is positioned on facing surfaces of the drying chamber body 5A and the open/close door 7A to make an inside of a drying chamber 25A airtight when the open/close door 7A is in a closed state; and a microwave leakage prevention mechanism 21 which is provided on a middle passage 63 between the opening part 3 and the seal structure 13 and is of a double choke integral structure where a first choke 17 and a second choke 19 are successively arranged facing each other in a circumferential direction at prescribed intervals.