Disclosed is a substantially water-based medical hydrogel having at least 0.010 but no more than 50 crosslink points per molecule, as well as a dried material thereof. The hydrogel is obtained by crosslinking a gelatin having 20 to 30 amino groups per molecule and the same or greater number of carboxyl groups per molecule or a gelatin derivative having 2 to 100 amino groups per molecule and 50 or more carboxyl groups per molecule. According to the present invention, a medical hydrogel with properties appropriate to the intended use can be reliably prepared. In particular a continuous delivery interval can be reliably achieved by using the hydrogel of the invention as a drug delivery vehicle.