The process of creating orthophotomaps from aerial photographs is complex and requiring the specialist software on the digital photogrammetric station. However, it turns out that this process with certain limitations can be executed by the Internet. Even, if there is a simplified solution, its didactic and functional advantages are great. These advantages induced the authors to work out the appropriate method of the realization of such a problem. In the article the solution of generating orthophotomap via the Internet is described. On account of the availability of the presented solution the author decided to use the client-server architecture of the application, in which the Internet browser of the user is a client (a program accesses a remote service on another computer by network). Applications of this type are being called web applications. The mathematical foundations of construction of orthoimage as a function are described. The algorithm of orthoimage generation is presented with the aid of UML diagram. The terrain coordinates of points, which are being used to create digital terrain model (DTM), are measured and calculated in the automatic way. However, the area of the orthophotomap is small and limited by dimension of the window of the Internet browser. Thus, in the process of orthoimage creation via the Internet the authors assumed a simplified DTM in the form of the plane. Orthorectification is made on the server side but the grid coordinate system is superimposed on the orthophotomap by means of applet on the client side. Besause of resampling, the created orthoimage has a worse quality than a source image. Therefore, the source photograph with the system of coordinates is also presented. In both cases the image and terrain coordinates of point shown by the cursor are calculated and printed in the header of the Internet browser window. The described application works on the Department of Photogrammetry and Remote Sensing UWM server http://www.kfit.uwm.edu.pl/zp1/or.html