Provided is an amorphous body of 9-ethyl-6,6-dimethyl-8-(4-morpholine-4-yl-piperidine-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile and a solid dispersion containing the amorphous body, being useful as a medicine for oral administration.9-乙基-6,6-二甲基-8-(4-嗎啉-4-基-哌啶-1-基)-11-側氧基-6,11-二氫-5H-苯并[b]咔唑-3-甲腈之非晶質體及包含該非晶質體之固體分散體係非常有利於作為用於經口投予用藥劑。