A flow-channel with the sub-micrometer depth was fabricated aiming highly sensitive SPR sensing. The channel structure and anodic bonding conditions based on a BK7 glass substrate were optimized. The formation of the submicrometer-depth fluidic channel was confirmed by scanning electron microscopy. Water and electrolyte solutions penetrated the prepared flow-channel by capillary force. SPR curves obtained with the fabricated flow-channel to the concentration of an electrolyte solution, which indicated that the fabricated nanofluidic channel is applicable for SPR sensing.