The invention provides a digital camera having a viewfinder with an adjustable length. The digital camera includes a first viewfinder member, a second viewfinder member, a first resilient member, a first engagement member, and a second engagement member. In this invention, the first viewfinder member is mounted in the digital camera. The second viewfinder member is mounted in the first viewfinder member and is capable of sliding relative to the first viewfinder member. The first resilient member is connected to the second viewfinder member and capable of pushing the second viewfinder member from a ready position to an ejected position. The first engagement member is mounted on the second viewfinder member. The second engagement member cooperates with the first engagement member so as to press against the first engagement member to keep the second viewfinder member at the ready position when the second engagement member is at an engaged position, and to be pushed toward the ejected position by the first resilient member when the second engagement member moves toward a non-engaged position.