Let p be an odd prime number which splits into two distinct primes in an imaginary quadratic
field K. Then K has certain kinds of noncyclotomic $\Z_p$-extensions
which are constructed through ray class fields with respect to a prime ideal
lying above p.
We try to show that Iwasawa invariants $\mu$ and $\lambda$ both vanish
for these specfic noncyclotomic $\Z_p$-extensions.