An underfill material achieving a wide margin for mounting and a method for manufacturing a semiconductor device using the same are provided. The underfill material contains an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide, wherein a minimum melt viscosity attainment temperature and a minimum melt viscosity obtained when melt viscosity of the underfill material is measured under a temperature increase rate condition in a range of 5 to 50° C./min are in a range of 100° C. to 150° C. and in a range of 100 to 5000 Pa·s, respectively. Since variation in the minimum melt viscosity attainment temperature measured under different temperature increase conditions is small, voidless mounting and good solder bonding properties can be achieved without strict control on the temperature profile during thermocompression bonding, and a wide margin for mounting can be achieved.