Here's a starting point for you

Note that as @percusse said in his comment, you need to use alignment tabs even for columns that are empty. I've made use of the \cline command which stands for column line and has syntax
\cline{startingcolumn-endingcolumn}
so for example, \cline{2-7} draws a line from the 2nd column to the 7th column.
I've also loaded the geometry package just to enlarge the page size- you'll want to make sure it can fit inside your document.
For further reading, you might like to look at
multirow package which would help with spanning across multiple rows
caption to get rid of the : when your caption is empty (and also helps to customize captions globally)
booktabs to help make beautiful tables. A lot of folks would recommend omitting the vertical lines, but I'll leave that up to you
MWE:
\documentclass{article}
\usepackage{geometry}
\begin{document}
\begin{table}
\centering
\begin{tabular}{|c|c|c|c|c|c|c|}
\hline
\multicolumn{2}{|c|}{Koszt naprawy} &\multicolumn{5}{|c|}{Czas wykrycia} \\ \cline{3-7}
\multicolumn{2}{|c|}{} & Wymagania & Architektura & Programowanie & Testy & Po dostarczeniu \\ \hline
Czas Wystapienia & Wymagania & 1x & 3x & 5-10x & 10x & 10-100x \\\cline{2-7}
& Architektura & - & 1x & 10x & 15x & 25-100x \\\cline{2-7}
& Programowanie & - & - & 1x & 10x & 10-25x \\\hline
\end{tabular}
\caption{.}
\end{table}
\end{document}
& &in the end of the row. You can't skip them even if they are empty. Also remove the empty line. – percusse Aug 27 '12 at 20:36