\begin{abstract_eng}
Haskell is a purely-functional programming language.
It provides a modern type system, type-safe and type inference makes it possible to write a program reliable\cite{types}.
Haskell has referential transparency that allows the programmer and the compiler to reason about program behavior.

In this study, we implement the parallel database using Haskell.
It is use non-destructive tree structure.
Non-destructive tree structure is not the destruction of data.
Editing of data is done creating by new tree.
Haskell compatible with non-destructive tree, because Haskell is destructive updates does not exist

We measures the performance for reading and writing of parallel database.
We achieve to bring out the performance of the multi-core processor.
Further, in order to indicate the availability of practical applications, we have developed a Web bulletin board service.
\end{abstract_eng}