This work presents an approach to simulate laser cutting of ceramic substrates utilizing a phase field model for brittle fracture. To start with, the necessary thermoelastic exten- sion of the original phase field model is introduced. Here, the Beer-Lambert law is used in order to model the effect of the laser on the substrate. The arising system of partial dif- ferential equations - which comprises the balance of linear momentum, the energy balance and the evolution equation that governs crack propagation - is solved by a monolithic fi- nite element scheme. Lastly, the influences of the laser power and the initial groove size on the manufactured work piece are analyzed numerically in simulations of a laser cutting process.