A new Galvanomagnetic electrorootive force effect of $Ni_{53}-Fe_{47}$ thin films is studied. The dependence of this effect on $ heta$, angle between the current and the magnetic field, is found to be the form of sin $2 heta$, in contrast with that of the magneto resistance effect cas $2 heta$ and that of the Hall effect sin $ heta$. Property of this effect is that lthe rate of the voltage variation depending on the magnetic field is extremely large as compared with the magnetiresistance effect. It is theoretically confirmed that this effect is well understood on the basis of the two carrier types model.