An electronic instrument has an instrument body 2, an operation unit 3, and an engagement link 4. The engagement link 4 removably attaches the operation unit 3 to the instrument body 2. The engagement link 4 has a first joint member 22 and a second joint member 23. The first joint member 22 engages with a lower end 3a of the operation unit 3. The second joint member engages with an upper end 3b of the operation unit 3. The link mechanism moves the second joint member 23 to release the second joint member 23 from the upper end 3b when the first joint member 22 moves toward an engaging position of the first joint member 22 with the lower end 3a. The link mechanism can move the second joint member 23 to engage with the upper end 3b while the first joint member 22 has been engaged with the lower end 3a.