The current study examines the use of 1-(naphthoxyacetyl)-4-ethyl-3-thiosemicarbazide (H2NAET) as an inhibitor against corrosion in 1 M HCl. Mass loss (ML) and potentiodynamic polarization (PP) studies are two methods used to confirm the tested compound's inhibitory effect. The results show that increasing the temperature and inhibitor concentration improved inhibition potency. The adsorption of H2NAET on carbon steel follows the Langmuir adsorption isotherm and the inhibitor functions as mixed corrosion inhibitor. Atomic force microscopy (AFM) was used to analyze the surface. The gathered data showed that a preservative layer of the inhibitor had developed on the surface of the carbon steel.