  We have developed a new calorimeter for measuring thermodynamic properties in
pulsed magnetic fields. An instrumental design is described along with the
construction details including the sensitivity of a RuO2 thermometer. The
operation of the calorimeter is demonstrated by measuring heat capacity of
three samples, pure Germanium, CeCu2Ge2, and $\kappa$-(BEDT-TTF)2Cu[N(CN)2]Br,
in pulsed fields up to 43.5 T. We have found that realization of
field-stability is a key for measuring high-resolution heat capacity under
pulsed fields. We have also tested the performance of the calorimeter by
employing two measurement techniques; the quasi-adiabatic and dual-slope
methods. We demonstrate that the calorimeter developed in this study is capable
of performing high-resolution calorimetry in pulsed magnetic fields, which
opens new opportunities for high-field thermodynamic studies.
