A sensing apparatus includes a fluxgate module which outputs an analog signal corresponding to terrestrial magnetism using a fluxgate having a magnetic substance core and a driving coil, and an analog-to-digital (A/D) converter which converts an analog signal output from the fluxgate module into a digital signal. The fluxgate module includes first and second current amplifiers for exciting the magnetic substance core by applying pulses to first and second ends of the driving coil, and a pulse restricting part for driving the first and second current amplifiers to apply the pulses and for stopping driving the first and second current amplifiers when converting the analog signal into the digital signal is completed.