This study aims to evaluate the characteristics of activated carbon from corn husk pyrolysis at 400°C. Cornhuskcharcoal was activated using HCl solution with concentrations of 1, 1.5, and 2 N for 24 hours, then washeduntil neutral, and dried at 110°C. Characterisation was carried out using Fourier Transform Infrared Spectroscopy (FTIR) to identify functional groups. Scanning Electron Microscopy (SEM) was used to study surface morphology, whileX-Ray Diffraction (XRD) provided information on the crystal structure. The specific surface area, pore volume, andpore size distribution were determined using Brunauer-Emmett-Teller (BET) analysis and the N2 adsorption- desorption method. The results showed that activation with HCl at a concentration of 1.5 N led to significant changes in the physicochemical properties. In addition, the specific surface area increased from 7.70 m2 /g to 22.48m2 /g, the total pore volume increased from 0.0555 cm3 /g to 0.0683 cm3 /g, and the average pore diameter decreasedfrom 28.8 nm to 12.1 nm. FTIR spectrum showed a decrease in the intensity of hydroxyl and aromatic groups, indicating a reduction in lignocellulose content, while the SEM image revealed a more porous and fragmentedsurface after activation. XRD analysis showed an amorphous nature with a broad peak at around 2θ ≈ 22° andanincrease in local intensity after activation. These changes in texture and chemical aspects indicated that HCl activation was effective in improving the characteristics of activated carbon from corn husk, making it a low-cost adsorbent candidate for environmental applications.