(Updated to include @Mico's suggestion of a \bigskip.)
Here's one possibility that makes use of \parboxes. This solution makes sense, I think, if you want all of the figures to have a figure number that increases.
You can change the length for the first two \parboxes and the length for the first two \includegraphics commands if you want the top two figures to be smaller and not span the entire width of the overall figure environment.
\documentclass{article}
\usepackage{graphicx}
\usepackage{mwe}
\begin{document}
\begin{figure}
\parbox{.48\textwidth}{\includegraphics[width=.48\textwidth]{example-image-a}\caption{}}
\hfill
\parbox{.48\textwidth}{\includegraphics[width=.48\textwidth]{example-image-a}\caption{}}
\bigskip
\parbox{.32\textwidth}{\includegraphics[width=.32\textwidth]{example-image-a}\caption{}}
\hfill
\parbox{.32\textwidth}{\includegraphics[width=.32\textwidth]{example-image-a}\caption{}}
\hfill
\parbox{.32\textwidth}{\includegraphics[width=.32\textwidth]{example-image-a}\caption{}}
\end{figure}
\end{document}

There are also the subfig and subcaption packages that allow you to have subfigures (e.g., the labels will be something like Figure 1(a), Figure 1(b), etc.; see, for starters, subcaption vs. subfig: Best package for referencing a subfigure and also Jesse's answer for a concrete example).
\medskipor\bigskip, between the two groups of figures. Otherwise, it's not immediately clear where the first two captions belong. – Mico Mar 14 '14 at 13:12