To reduce background light generated in a circumference of a scatterer in a head for a thermally assisted magnetic recording device using a scatterer having conductivity as an optical near-field generating element, a coil for generating a magnetic field is placed on a bottom portion of a slider, and an optical near-field generating element is placed in an inside of the coil. At this time, an inner diameter of the coil is set not larger than a wavelength of incident light, an interval between leader lines each for conducting an electric current to the coil is set not larger than a half of the wavelength of the light, and the coil for generating the magnetic field is caused to function as a shield for suppressing the background light.