Steering device of working vehicle and method of controlling steering device of working vehicle

A steering device of a working vehicle, comprising:

• a lever which performs tilting operation for steering;
• a first switch for setting a steering signal from the lever to be in a valid/invalid state;
• a lever support member which is provided so as to be able to flip up from a certain position of performing tilting operation with use of the lever and supports the lever;
• a second switch which attains conduction when the lever support member is located at the certain position, and attains non-conduction in conjunction with a case where the lever support member is flipped up from the certain position;
• and
• a control device for setting steering with use of the lever to be valid/invalid, wherein
• the first switch having a plurality of terminals which attain conduction of a steering signal from the lever in accordance with setting of a valid state and an invalid state and are electrically connected to the control device in parallel with the second switch, and
• the control device determines an abnormal state in accordance with an input order of signals inputted based on the first and second switches.