To provide a concealed postcard with high security.

The concealed postcard 10 comprises: a postcard body 11 provided with a confidential information writing column 111; and a concealing part 12 continuously provided to the postcard body 11 with a perforated line m therebetween, and for covering at least the confidential information writing column 111 by folding back on the perforated line m. The concealing part 12 is formed by laminating at least a separation layer 14, a resin transfer layer 15, a pressure-sensitive adhesive layer 16, and a separation sheet 17 on a concealing base material 13, and the resin transfer layer 15 has brittleness of degree substantially inseparable from the postcard body 11, when transferred to the confidential information writing column 111 together with the pressure-sensitive adhesive layer 16.