Disclosed is an in-cell touch display device for preventing direct current DC accumulation from being caused by a DC voltage electric field despite using a high-resistance black matrix. The in-cell touch display device may include the passivation layer that covers the back transistor. The passivation layer may block a DC voltage electric field or may disperse electric charges accumulated based on the DC voltage electric field, and thus, even in a case where the high-resistance BM is used, DC accumulation is not caused by the DC voltage electric field. Accordingly, the in-cell touch display device prevents the DC accumulation from being caused by the DC voltage electric field despite using the high-resistance BM, thereby reducing adsorption of a pollution component.